After finishing the calculation, you will obtain the four files listed above.
The first three files will be read by 'wannier90.x' of Wannier90, and the last file 'System.Name.win' is
an input file to handle the calculation of 'wannier90.x'.
The schematic computational flow is shown in Fig. 40.
With the overlap matrix 'System.Name.mmn', the projection matrix 'System.Name.amn',
and eigenvalues 'System.Name.eig', maximally localized Wannier functions are calculated
by using 'wannier90.x'.
After getting the maximally localized Wannier functions, by using 'postw90.x' of Wannier90
you can calculate a variety of physical properties
such as Berry phase related properties (anomalous Hall conductivity and optical conductivity)
and thermoelectric properties.
In the file 'System.Name.win' the default setting is for the calculation of optical conductivity as

berry_task kubo

By changing the option for the keyword 'berry_task' properly, you may be able to calculate other physical quantities.
Some of the options for the keyword are listed below:

As for the more details of Wannier90, please refer to the web site of Wannier90 [99].

As examples, Figures 41 and 42 show
Seebeck coefficient of silicon in the diamond structure and optical conductivity of SrVO, respectively,
calculated by interfacing OpenMX with Wannier90 with the above mentioned scheme.
The input files 'Si-Wannier90.dat' and 'SrVO3-Wannier90.dat' can be found in the directory 'work'.

Figure 40:
Schematic computational flow for the interface of OpenMX with Wannier90.

Figure 41:
(a) Band structure of silicon in the diamond structure, calculated by 8 Wannier orbitals
constructed from OpenMX and Wannier90 calculations, and (b) Seebeck coefficient at T=300K
estimated from the 8 Wannier bands. The input file used for the OpenMX calculation is 'Si-Wannier90.dat'
which is found in the directory 'work'.

Figure 42:
(a) Band structure of SrVO,
(b) optical conductivity of SrVO calculated by interfacing OpenMX with Wannier90,
which is well compared to an experimental optical conductivity in Ref. [100].
The input file used for the OpenMX calculation is 'SrVO3-Wannier90.dat' which is found in the directory 'work'.